446 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
tion of its 'song' will be found in Scudder's "Distribution of 
Insects in New Hampshire" and also in the 23d Report of the 
Entomological Society of Ontario (1893, p. 76). 
Broad-winged Sedge-locust. 
Mecostethus platypterus (Scudder). 
Plate 20, fig. 25-27. 
Arcyptera platyptera Scudder, Boston Journ. Nat. Hist., vol. 7, p. 463 
(1862). 
Mecostethus platypterus Morse, Psyche, vol. 7, p. 445 (1896). — Walden, 
Bull. Geol. Nat. Hist. Surv. Ct., no. 16, p. 85 (1911). 
Vertex broad, blunt, full, with margins little elevated and 
mid-carina more prominent. Lateral foveolae absent or showing 
but as faint traces. Pronotum with hind margin little extended, 
prozone equal to metazone, lateral carinae parallel or very 
nearly so, continuous, faintly cut only by principal sulcus. 
Surface of disk of pronotum with minute longitudinal ridges. 
Prosternum less protuberant than in either of its congeners. 
Subgenital "plate of male short, conical, about one and a half 
times its depth. Valves of ovipositor with the base stouter, 
the outer edges of the upper pair a little more prominently 
toothed and with somewhat sharper tips than in M. lineatus. 
Total 
Male 26.8-29 
Female 34-40 
The brownish of the coloration is of a somewhat darker tint 
(bister) on the sides of the pronotum and head, and deepens 
into fuscous below the lateral carinae of the pronotum and 
behind the eyes. The hind tibiae are not annulate and their 
spines are slenderer and dusky only at the tip or scarcely at all. 
The red of the hind femora is less intense and often replaced 
by yellowish. As in M. gracilis, the dorsal field of the tegmina 
is distinctly paler than the lateral field and meets it at a more 
distinct angle. 
The parallel lateral carinae of the pronotum, the large head, 
wide vertex, and long antennae readily separate this species 
from M. gracilis, which otherwise it most resembles superficially. 
Measurements. 
Tegmina Tegmina 
Hind femora 
Antenna 
Length Width 
19-21 21 5 
15 -16.5 
11-12.5 
24-25 24.5 4.8 
17.6-20.6 
10-11 mm, 
